The proposed work involves a study of the interactions between the products of antigen-stimulated immunocompetent cells and other cell types in various forms of cell-mediated immunity. Specific approaches include (1) delineation of specific lymphocyte subpopulations which produce lymphokines, (2) exploration of the In vivo behavior of certain lymphokines, (3) isolation, purification and characterization of lymphokines and lymphokine-like factors and (4) determination of mechanisms of cell activation for lymphokine production and regulation of lymphokine production and function. We have demonstrated the role of simple monosaccharides in regulating the activity of lymphokines, defined a mechanism for the control of B cell-derived MIF production, and have initiated studies on murine lymphokines. In addition to continuing these studies, we have begun investigations into the role of macrophages as helper cells in lymphokine production.